If I read this correctly they CANNOT be arrested in their respective House or to and from EXCEPT for treason, felony and breach of the peace. Which in my book just about covers most crimes except petty ones so I would say they could be arrested in the House.
You cannot arrest them to prevent them from going to a vote or a debate. That is ALL this means. T IS NOT a blanket exemption to Congress to ignore following the law. You are invoking a "Right" that is NO way involved IN this matter. No one prevented the Congressman from doing his job. His office is NOT a sanctuary where he can hid from the rule of law simply because he is a Congress critter. Equal protection Clause? Heard of it. You are claiming special privileges for Congresscritters. That nonsense.